Recently, in the medical field, support arm apparatuses are being used to support surgeries and examinations. For example, a method is proposed in which an observation unit such as a camera for observing a surgical site is provided on the front edge of an arm unit of a support arm apparatus, and the surgeon performs surgery while viewing an image captured by the observation unit. Also proposed is a method of causing a support arm apparatus to perform work that has been done manually in the past, such as supporting a treatment tool such as forceps with the arm unit of a support arm apparatus.
At this point, generally, in medical electrical equipment (ME equipment), it is necessary to provide the insulation demanded by a certain safety standard (for example, the international safety standard IEC 060601-1) to protect the patient and the operator (surgeon). For example, in the case of a support arm apparatus having a movable mechanism in which an actuator is provided in a joint unit, there is demand to insulate the motor of the actuator so as to satisfy a certain safety standard.
For example, as a technology related to the insulation of a motor, Patent Literature 1 discloses a technology whereby the outer casing of the motor is made up of an insulating resin. According to this technology, by having the thickness of the insulating resin constituting the outer casing satisfy a required thickness determined by a safety standard, it becomes possible to ensure high reliability with regard to safety factors such as shock prevention.